HUT72327A - 8-substituted xanthines as selective adenosine receptor agents - Google Patents

Description

8-substituted xanthines with selective adenosine action

Merrell Dow Pharmaceuticals Inc., CINCINNATI, Ohio,

USA

Inventors: PEET Norton Paul, CINCINNATI,

LENTZ Nelsen Lowell, WEST CHESTER,

Ohio, USA

Date of filing: 13/04/1994

Priority: 06/06/1993 (08 / 058,523)

USA

International Application Number: PCT / US94 / 04038

International Publication Number: WO 94/26744

The present invention relates to xanthine derivatives which selectively act on adenosine receptors.

The highly potent antihypertensive, sedative, anticonvulsant and vasodilator effects of adenosine were demonstrated 50 years ago, and many other biological effects of adenosine have been discovered in research since then. Adenosine receptors bind to adenylate cyclase in many cells. In recent years, several adenosine analogs have been produced to test these receptor functions. The best known antagonists of adenosine receptors are alkyl xanthines such as caffeine and theophylline.

Adenosine is probably a generic regulator because no cell type or tissue can be associated with its formation in the cell or tissue. In this respect, adenosine is not similar to various endocrine hormones. It could not be shown that adenosine is stored or released from nerve cells or other cells. Therefore, adenosine is also not similar to various neurotransmission agents.

In terms of its physiological regulatory role, adenosine can be compared to prostaglandins. In both cases, the enzymes involved in metabolite formation are ubiquitous enzymes and appear to alter the physiological processes of the cell state. Adenosine receptors, like prostaglandin receptors, are found in a very wide area. Finally, both prostaglandins and adenosine are involved in processes that regulate the function of calcium ions. Of course, prostaglandins are derived from membrane precursors, while adenosine is derived from cytosolic precursors.

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- 3 Although adenosine plays a role in many physiological processes, research has primarily focused on its effects that allow its clinical application. The cardiovascular or cardiovascular effects of adenosine, which may result in vasodilation and hypotension, but may also lead to a decrease in cardiac function, have been primarily studied. The anti-lipid, anti-thrombotic and anticonvulsant effects of adenosine have also been studied. Adenosine stimulates steroid formation in adrenal cells and is likely to be activated by adenylate cyclase. Adenosine has an inhibitory effect on the neurotransmission (neurotransmission) and spontaneous activity of the central neurons. Finally, adenosine has a bronchodilatory effect and, as a result, the antagonistic effect of xanthines on it is the subject of research.

In our studies, we recognized that not one but at least two extracellular receptor classes play a role in adenosine activity. One class of receptors has a very high affinity for adenosine and is bound in at least some cells by inhibition by adenylate cyclase. These receptors are called A-1 receptors. The other group of receptors has a low affinity for adenosine and binds to adenylate cyclase in a stimulatory manner in many cells. These receptors are called A-2 receptors.

Adenosine receptors have been characterized by several structural analogues. Adenosine analogue compounds resistant to metabolism and uptake mechanism have been prepared. They are particularly advantageous because they are less excreted from the system of action because this is not possible by metabolism. The various adenosine analogues show different binding to the A-1 and A-2 adenosine receptors, thus providing a simple method for characterizing the physiological response function of the various adenosine receptor types. Blocking adenosine receptors (antagonistic effect) is another way to do this

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- The role of the 4 adenosine receptors in different processes is characterized. It should be noted that the development of antagonists that specifically bind to A-1 or A-2 adenosine receptors poses great difficulty in the research, as it has not been possible to produce adenosine receptor selective pharmacologically active agents that are physiologically active in individual mammals or animals. would be specific.

European Patent Application 0,449,174 A2 discloses various xanthine derivatives which exhibit specific selective action at adenosine receptors and which are generally adenosine antagonistic. International patent application WO 92/00297 describes novel xanthine derivatives as well as the process for their preparation and their use as a pharmaceutical active ingredient. U.S. Patent 5,047,534 discloses xanthine derivatives which generally have an adenosine antagonistic action. The present invention relates to novel xanthine derivatives which exert selective action on adenosine receptors.

The present invention relates to compounds of formula (I), including their (R) - and (S) -enantiomers and their racemic mixtures, and pharmaceutically acceptable salts thereof, wherein:

R ₁ and R ₂ are each independently C 1-4 alkyl or C 2-4 alkenyl;

Z is (c) or (d) or (b) wherein R ₃ is hydrogen, C 1-3 alkyl, nitro, amino, hydroxy, fluoro, bromo, or chloro;

R ₄ is C 1-4 alkyl; and n is an integer of 1 or 2.

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The term "C1-C3 alkyl" as used herein refers to, for example, methyl, ethyl, n-propyl or isopropyl. As used herein, "C 1-4 alkyl" refers to methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl.

Further, the term "C2-C4 alkenyl" as used herein includes ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, and the like. means.

Further, the term R ₃ is present at any position 2-6 of the phenyl group or at the 5-8 position of the 1,2,3,4-tetrahydronaphthyl group. When the substituent is other than hydrogen, there may be up to three independent substituents on these ring systems.

The compounds of the present invention are generally shown in Scheme I and Scheme II. the reaction scheme.

The appropriately substituted starting materials of formula (I) is 6-amino-2,4 (1H, 3H) -pyrimidinedione, wherein in the formula R, and _R2 are as previously defined.

The starting material, 6-amino-2,4- (1H, 3H) -pyrimidinedione, was suspended in a 20% aqueous acetic acid solution. Subsequently, 1.5 equivalents of an aqueous solution of sodium nitrite was added (slightly concentrated acidic acid) to the solution at pH slightly acidic. The mixture was filtered and the precipitate was rinsed with water and dried in vacuo. A purple solid alkyl-substituted-6-amino-5-nitroso-2,4- (1H, 3H) -pyrimidinedione (2) is obtained.

Subsequently, the alkyl-substituted-6-amino-5-nitroso-2,4- (1H, 3H) -pyrimidinedione was suspended in water and the aqueous mixture was basified to pH 11 with 50% ammonium hydroxide solution. The mixture is then treated with an excess of sodium

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Mix with 6 µm-dithionite until the purple color fades. The reaction mixture was extracted with chloroform, and the organic extract was combined and dried over anhydrous magnesium sulfate. The organic solution was then filtered and concentrated in vacuo. The residue was purified by flash chromatography using a gradient of 5% to 10% methanol / chloroform. The material was then recrystallized from 10% isopropanol / hexane to give alkyl-substituted-5,6-diamino-2,4- (1H, 3H) -pyrimidinedione (3). (J.W. Daly, J. Med. Chem., 28, 487, 1985).

The compound of formula (3) prepared according to Scheme I is then all-reacted. Reaction Scheme III. All substituents in the reaction scheme are as previously defined and R 1 and R ₂ 'are C 2 -C 4 alkyl.

All. In Scheme A, Step A, the alkyl-substituted-5,6-diamino-2,4- (1H, 3H) -pyrimidinedione (3) is reacted in the amidation reaction with the corresponding substituted acid (3a), according to the literature. by a well known procedure to provide the corresponding substituted amide of formula (4).

For example, the appropriately substituted acid of formula 3a is dissolved in a suitable solvent such as tetrahydrofuran. Suitable substituted acids of the general formula (3a) include 3-phenylbutanoic acid, 1,2,3,4-tetrahydro-2-naphthalic acid, and trans-2-phenylcyclopentanecarboxylic acid. Then, one equivalent of N-methylmorpholine was added to the acid solution and the mixture was cooled to -20 ° C. To the resulting reaction mixture was added 1 equivalent of isobutyl chloroformate and the reaction mixture was stirred for about 1 hour. Stir for 20 minutes. A solution of 1 equivalent of alkyl-substituted-5,6-diamino-2,4- (1H, 3H) -pyrimidinedione (3) in a suitable organic solvent is then added. Examples of the solvent include dimethylformamide

61,335 / SM. The reaction mixture was then stirred for ca. Stir for 3 hours at -20 ° C. The mixture is then diluted with a suitable organic solvent, such as diethyl ether, and then washed with saturated sodium bicarbonate solution and then with 50% or saturated sodium chloride solution. The organic solution was then dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. Thus, the appropriately substituted amide of formula (4) is obtained.

II. In Scheme B, Step B, the amide of formula (4) is reacted in a cyclization reaction according to procedures well known in the art (Peet et al., J. Med. Chem. 33, 3127 (1990)). Thus, the appropriately substituted 1,3-dialkyl-8-substituted-xanthine (compound of formula 5) is obtained.

For example, the appropriately substituted amide (4) is dissolved in a suitable organic solvent, such as ethanol, and then a 10 to 20% aqueous solution of a suitable base is added. The base is, for example, potassium hydroxide. The reaction mixture is then stirred for about 1-6 hours. Heat to 40-60 ° C. The reaction mixture was cooled and acidified with a suitable acid. As the acid, for example, hydrochloric acid may be used. The crude product is then extracted from the aqueous phase with a suitable organic solvent such as diethyl ether. The combined organic extracts were washed with water followed by brine, then dried over anhydrous magnesium sulfate, filtered and evaporated. Alternatively, the precipitated crude product is filtered from the acidic aqueous phase obtained as above. The residue or the filtered precipitate can then be purified by methods known in the art. Purification may be carried out, for example, by radial chromatography using a suitable eluent such as ethyl acetate / hexane to give the appropriately substituted 1,3-dialkyl-8-substituted-xanthine (5).

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- 8 All. In Scheme C, Scheme C, optionally, 1,3-dialkyl-8-substituted xanthine (5) is hydrogenated when R ₁ and R ₂ are C 2 -C 4 alkenyl at the 1,3-dialkyl position. Thus, an appropriately substituted-1,3-dialkyl-8-substituted-xanthine of formula (6) is obtained wherein the 1,3-dialkyl substituents are R 1 and R ₂ 'which are C 2 -C 4 alkyl.

For example, a suitably substituted-1,3-dialkyl-8-substituted-xanthine compound of formula (5), such as 1,3-diallyl-8-substituted-xanthine, is dissolved in a suitable organic solvent, such as methanol. A catalytic amount of a suitable hydrogenation catalyst, which may be palladium on activated carbon, is then added to the mixture, and the reaction mixture is placed under an atmosphere of hydrogen and ca. Stir for 30 minutes to 4 hours. The reaction mixture is then purged with inert gas, such as nitrogen, and then filtered and concentrated in vacuo. The residue can be purified by methods well known in the art. The purification process may be, for example, radial chromatography using a suitable eluent such as ethyl acetate / hexane. Thus, appropriately substituted-1,3-dialkyl-8-substituted-xanthine (6) is obtained.

Examples of the compounds of the present invention prepared by the process of the present invention include:

8- (2-phenylpropyl) -1,3-dipropyl-3,9-dihydro-purine-2,6-dione;

1,3-dipropyl-8- (1,2,3,4-tetrahydronaphthalen-2-yl) -3,9-dihydropurine-2,6-dione; and 8- (trans-2-phenylcyclopentyl) -1,3-dipropyl-3,9-dihydropurine-2,6-dione.

Therapeutic utility of selective adenosine receptor drugs

The following table shows in detail the therapeutic uses of the selective adenosine receptor agents of the present invention:

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Field of application Effect Interacting receptor

Cardiovascular cardiac enhancer A-1 antagonist Cardiovascular regulation of tachycardia A-1 agonist Cardiovascular increase coronary blood flow A-2 agonist Cardiovascular vasodilator A-2 (atypical) agonist Lungs bronchodilator A-1 antagonist Lungs autocoid release in public projection from mast cells, basophils new adenosine receptor interaction on the cell surface Lungs respiratory stimulation; the paradox management of respiratory response (Csecsmökben) Tax antagonist Kidney inhibition of renin release A-1 aton Central nervous system opiate withdrawal management Tax agonist Central nervous system painkiller A-1 agonist Central nervous system anticonvulsant A-1 agonist Central nervous system antidepressant A-1 agonist Central nervous system antipsychotic effect Tax agonist Central nervous system anti-anxiety effect agonist Central nervous system inhibition of self-motility- (Lesch-Nyhan syndrome) Tax agonist Central nervous system sedative A-2 agonist

Scheduled compounds of the cardiovascular, pulmonary, and renal pathways, as defined above by appropriate receptor binding assays, may be tested in in vivo assays. In these assays, their human physiological activity can be directly determined. Pharmacology and ha61.335 / SM

A good description of the 10-step mechanism for purine receptors has been reported in M. Williams, Ann. Port. Pharmacol. Toxicol., 27, 31 (1987). The "therapeutic study of adenosine receptor modulators" described that "adenosine agonist agents are useful as antihypertensive agents, as well as in the treatment of opiate deprivation and as modulators of the immune system and renin release, as antipsychotic agents and as hypnotic agents. In contrast, antagonistic agents can be used as a central nervous system stimulant, an inotropic agent, a cardiac enhancer, an anti-stress agent, an anti-asthma agent, and in the treatment of respiratory diseases. ' Because of the diversity of activity of the active ingredients acting on the adenosine receptor, these agents are useful in the treatment of various diseases and require the development of specific active ingredients.

Adenosine exerts its various biological effects on receptors on the cell surface. These adenosine receptors are of two types: A-1 and A-2. The receptor-1, functionally they are characterized in that they bind ^N6 -substituted adenosine analogs, e.g. R-phenylisopropyl-adenosine (R-PIA) and cyclo-adenosine (CHA) and they are more effective than the 2 -chloroadenosine and N-5'-ethylcarboxamidoadenosine (NECA). In contrast, the binding order at A-2 receptors is NECA>2-chloroadenosine>R-PIA> CHA.

As described in the table above, adenosine receptors regulate many physiological functions. Two major types of adenosine receptors have also been identified. The two receptor types are the A-1 adenosine receptor, which inhibits adenylate cyclase and the A-2 adenosine receptor, which stimulates adenylate cyclase. The A-1 receptor has a greater affinity for adenosine and adenosine analogs than the A-2 receptor. Adenosine and adenosine

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The physiological effect of the 11 analogs is further complicated by the fact that non-selective adenosine receptor binding agents first bind to the ubiquitous low affinity A-2 receptor, and as the dose is increased, they bind to the high affinity A-2 receptor, and at much higher doses. they also bind very high affinity A-1 adenosine receptors. See J.W. Daly, et al., 1983, 1983, 3 (1), 69-80, Interaction with Caffeine and Related Methylxanthines, Cellular and Molecular Neurobiology.

In general, adenosine exerts its physiological effect either by stimulating or inhibiting adenylate cyclase. Activation of adenylate cyclase increases the concentration of intracellular cyclic AMP, which is generally considered to be an intracellular secondary messenger molecule. Therefore, the effect of the adenosine analogs can be measured or measured by their ability to increase the intracellular concentration of cyclic-AMP, i.e., to stimulate or antagonize it. Significant cell lines that can be tested in this regard are VA 13 (WI-38 VA 13 2RA), VS-40 transformed W 38 human fetal lung fibroblasts, which are known to contain the A-2 subtype adenosine receptor, and adipose cells known to be A They contain an adenisin receptor subtype -1. See R.F. Bruns, Adenosine Antagonism by Purines, Pteridines and Benzopteridines in Human Fibroblasts, Chemical Pharmacol., 30, 325-33 (1981).

It is well known in the art from in vitro studies that the 8-phenyl-1,3-dipropylxanthine acid analog (XCC) is a non-selective adenosine receptor drug with a K-value of 58 ± 3 nM and a K-value at A-1 brain membrane receptors. At the _2- receptor, 34 ± 23 nm in brain section assay. The activity of the 8-phenyl-1,3-dipropylxanthine amino analogue compound (XAC) on A-1 adenosine receptors is 40-fold higher and K, vas61,335 / SM

-12 was 1.2 ± 0.5 nm compared to K for the A-2 brain section test receptor, which is 49 ± 17 nm. In addition, XAC is much more potent in antagonizing the heart rate of adenosine analogues than in acting on blood pressure. It is generally known that the adenosine analog-induced effect on the heart is generally via the A-1 receptor and on the blood pressure via the A-2 receptor. The in vivo selectivity of the XAC agent shows that the in vitro adenosine receptor activity generally corresponds to the in vivo adenosine receptor activity and that the specific physiological effects resulting from the selectivity can be distinguished. See B.B. Fredholm,

K. Jacobsen, B. Jonzon, K.L. Kirk, Y.O. Li and J.W. Daly, Evidence That is also the Increased 8-Phenyl-Substituted Xantine Derivative, a Cardioselective Adenosine Receptor Antagonist In Carrier, Journal of Cardiovascular Pharmacology, 9, 396-400 (1987) and K.A. Jacobsen, K.L. Kirk. J. Daly, B. Jonzon, Y.O. Li and B.B. Fredholm, Increased 8-Phenyl-Substituted Xanthine Derivative Is Selective Antagonist At Adenosine Receptors In Vivő, Acta Physiol. Scand., 341-42 (1985).

It is also known that adenosine causes a significant reduction in blood pressure. The decrease in blood pressure is likely to be mediated by the A-2 receptor since a decrease in peripheral resistance is produced. In addition, adenosine analogues are capable of reducing heart rate. This effect is likely mediated by A1 adenosine subtype receptors.

It is evident from the above studies that administration of the adenosine receptor selective adenosine analog compounds of the present invention results in either binding to the A-2 or A-1 receptor for pharmaceutical purposes, which consequently results in a selective or decreased blood pressure or decrease in heart rate. carrier these physiological effects

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- 13 can be separated. The selection of such selective adenosine receptor drugs may be accomplished by the following assays.

Affinity test for brain adenosine A-2 receptors

The test assay determined the binding affinity of the test compounds for [ ³ H] -5'-N-ethylcarboxamidoadenosine (NECA) against adenosine A-2 receptors prepared from the animal brain membrane. See, for example, RR Bruns, GH Lu and TA Pugsley, Characterization of the A-2 Adenosine Receptor Labeled by [ ³ H] NECA in Rat Striatal Membranes, Mol. Pharmacol., 29, 331-346 (1986). Young male rats (CD strain) of Charles River origin were sacrificed by decapitation and the brain was removed. Ligand binding membranes were isolated from rat striatum in rats. The tissue was homogenized in 20 volumes of ice-cooled 50 mM Tris-HCl buffer (pH 7.7) using a polytron (set for 6-20 seconds). The homogenate was then centrifuged at 50,000 xg for 10 minutes at 4 ° C. The pellet was homogenized again in 20 volumes of buffer using a polytron and then centrifuged again as before. The pellet was finally suspended in 40 volumes of 50 mM Tris-HCl (pH 7.7) per gram of original wet tissue weight buffer.

Three replicate assays were performed and 100 μΙ [ ³ H] NECA (94 nm in the assay), 100 μΙ 1 μΓηοΙ cyclohexyladenosine (CHA), 100 mmol MgCl ₂ , 100 μΙ 1 IU / ml adenosine deaminase, 100 μΙ for each assay compound was added at various concentrations (10 ' ¹ ° m -10' ⁴ m) in assay buffer (50 mmol Tris-HCl, pH 7.7) and 0.2 μΙ membrane suspension (5 mg wet weight). . The final volume was 1 mL of 50 mM Tris-HCl, pH 7.7 buffer. Incubation was carried out at 25 ° C for 60 minutes. This is followed by 61.335 / SM

The contents of each test tube were filtered through a GF / B sintered glass filter using a vacuum. The filters were washed with 2 x 5 ml of ice-cooled buffer. The membrane precipitate on the filter was transferred to scintillation tubes to which 5 ml of Omnifluor 5% Protosol solution was added. The filters were then measured by liquid scintillation spectrometry.

Specific [ ³ H] NECA binding was measured by comparison with a blank prepared in the presence of 100 pmol of 2-chloroadenosine. Total membrane-bound radioactivity is approx. 2.5% of the radioactivity added to the test tubes. Since the total binding under these conditions is less than 10% of the radioactivity, the concentration of free ligand did not substantially change during the binding assay. The amount of specific binding to the membrane is approx. It was 50%. The protein content of the membrane suspension was determined by OH Lowry, NJ Rosebrough, AL Farr and RJ Randall, Protein Measurements with Folin Phenol Reagent, J. Bioi. Chem., 193, 265-275 (1951).

When the [ ³ H] NECA binding is replaced with a compound of the invention of 15% or greater, this indicates that the compound exhibits affinity for the A-2 type receptors. The concentration of compound that exerts 50% inhibition of ligand binding is the IC ₅₀ value. A value of 100-1000 nm means that the compound is very potent.

Affinity assay for adenosine A-1 receptor binding sites on brain preparations

The following assay was used to test the competitive effect of the test compounds of the present invention on binding to adenosine A-1 receptors, which were prepared from rat brain membrane compared to [ ³ H] -cycloadenosine ligand. Male Sprague-Dawley rats were sacrificed by decapitation, and the brain membranes were

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- Made of 15 brains. See R. Goodman, M. Cooper, M. Gavish, and S. Synder, Guanine Nucleotide and Cation Regulator of Binding of H, Diethylphenylxanthine to Adenosine A-1 Receptors in Brain Membrane, Molecular Pharmacology, 1982, 21,329-335. .

The membrane composition was homogenized with a polytron at 25 positions in 25 volumes of ice-cold 50 mM Tris-HCl pH 7.7 for 10 seconds. The homogenate was centrifuged at 19,000 rpm for 10 minutes at 4 ° C. The pellet was resuspended and washed in 25 volumes of buffer containing 2 IU adenosine deaminase per ml. The mixture was then incubated for 30 minutes at 37 ° C. The homogenate was then centrifuged again. The final pellet was resuspended in 25 volumes of ice-cooled buffer.

Calculate three replicate samples in incubation tubes at 100 μΙ [ ³ H] cyclohexyl-adenosine at 0.08 nm in the assay medium, 200 μΙ in various concentrations of the test compound solution (where the concentration ranges from 10 ^{10 10} m to 10 ^{6 6} m and dilution with 50 nm Tris-HCl buffer pH 7.7) 0.2 ml membrane suspension (8 mg wet weight) was added and the final volume was adjusted to 2 ml using Tris buffer. The incubation was then carried out for 2 hours at 25 ° C and was completed within 10 seconds by filtration on a GF / B glass-sintered filter using vacuum filtration. The membranes on the filter were then transferred to scintillation vials. The filtrate was counted by liquid scintillation spectrometry with 8 ml of Omnifluor containing 5% Protosol.

Specific binding of ^[3 H] cyclo-adenosine compared to the blank, measured 10 ^"5 M 2-chloroadenosine presence. Specific binding to the membranes is approximately. the

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was 90% of total binding. The protein content of the membrane suspension was performed as described in Lowrey et al., P.

If the test compound replaced the [ ³ H] cyclohexyl-adenosine binding by 15% or greater, this indicated that the active substance had an appropriate affinity for the adenosine binding site.

Adenosine receptor binding affinity values obtained in the assay methods described above

The table below shows the adenosine receptor binding affinity values for several compounds.

Adenosine receptor binding affinity Δι-Off a ₂ j ^ A _? / Rec 8- (2-phenylpropyl) -1,3-dipropyl-3,9- 94.3 nm 1740 nm 18 dihydro-purine-2,6-dione 1,3-dipropyl-8- (1,2,3,4-tetrahydronaphthalene) 94.6 nm 10300 nm 108 -2-yl) -3,9-dihydro-purine-2,6-dione 8- (trans-2-phenyl-cyclopentyl) -1,3- 164.3 nm 2720 nm 10

dipropyl-3,9-dihydro-purine-2,6-dione

The nucleotide guanosine triphosphate (GTP) has been shown to act differently to antagonist and agonist active substances of various neurotransmitter receptors. Generally, guanine nucleotide compounds decrease the affinity of agonist drugs for receptors, but do not simultaneously decrease the affinity of antagonists. Accordingly, GTP compounds reduce the potency of agonists but do not reduce the potency of antagonists such as inhibition of the binding of the adenosine antagonist [ ³ H] 3-diethyl-8-phenylxanthine. In general, GTP compounds greatly reduce the potency of purine agonists, but do not diminish the potency of antagonists that are [ ³ H] -phenylisopropyl61.335 / SM

- inhibit 17-adenosine binding. Consequently, these compounds can be used to discriminate between agonists and antagonists. See L.P. Davies, S.C. Chow, J.H. Skerritt, D.J. Brown and G.A.R. Johnston, Pyrazolo [2,3-d] -Pyrimidines as Adenosine Antagonists, Life Sciences, 34, 2117-28 (1984).

Pharmaceutical preparations of adenosine receptor active substances

The preferred route of administration is oral administration. For oral administration, the compounds of the invention may be formulated into solid or liquid compositions such as capsules, pills, tablets, cachets, lozenges, melts, powders, solutions, suspensions, or emulsions. The solid unit dosage forms may be, for example, capsule forms, which may be the usual hard or soft gelatin capsules, and may contain, for example, surfactants, lubricants and inert fillers which may be lactose, sucrose, calcium phosphate and corn starch. Alternatively, the compounds of the present invention may be formulated into a tablet form with commonly used tablet bases such as lactose, sucrose, corn starch, and lubricants such as acacia, corn starch, or gelatin, disintegrating agents, to aid dissolution of the tablet after administration and e.g. potato starch, alginic acid, corn starch and guar gum. In addition, lubricants which improve the flowability of the tablet granulate and prevent the tablet material from adhering to the tablet pressing tool, and which may be talc, stearic acid or magnesium, calcium or zinc stearate, may be used in the composition, and may contain dyes, colorings and flavors. which make the tablet form more acceptable to the patient. Diluents for oral liquid dosage forms include water and alcohols such as ethanol, benzyl alcohol, and polyethylene alcohols, and the like.

Pharmaceutically acceptable surfactants, suspending agents or emulsifying agents may also be included.

The compounds of the invention may also be administered parenterally, which may be by subcutaneous, intravenous, intramuscular or intraperitoneal administration, and in this form injectable doses of the compound of the invention may be prepared with a pharmaceutically acceptable diluent or pharmaceutically acceptable carrier. The carrier may be a sterile liquid or a mixture of liquids, such as water, physiological saline, aqueous dextrose solution and the like, and alcohol such as ethanol, isopropanol or hexadecyl alcohol, glycol such as propylene glycol or polyethylene glycol, glycerol. a ketal such as 2,2-dimethyl-1,3-dioxolane-4-methanol, an ether such as polyethylene glycol 400, an oil, a fatty acid, a fatty acid ester or glyceride or an acetylated fatty acid glyceride; The composition may optionally contain a pharmaceutically acceptable surfactant such as soap or detergent, a suspending agent such as pectin, carbomers, methylcellulose, hydroxypropylmethylcellulose or carboxymethylcellulose, and may include emulsifiers or other pharmaceutical additives. Oils which may be used in the formulation during administration are, for example, petroleum, animal, vegetable or synthetic oils, such as peanut oil, soybean oil, sesame oil, corn oil, cottonseed oil, olive oil, petrolatum and mineral oil.

Suitable fatty acids for use in the composition include oleic acid, stearic acid and isostearic acid. Useful fatty acid esters include ethyl oleate and isopropyl myristate. Suitable soaps include, for example, the alkali metal ammonium and triethanolamine salts of fatty acids. Suitable detergents include, for example, cationic detergents, such as dimethyldialkylammonium halides and alkylpyridinium halides; anionic detergents such as alkyl, aryl

61.335 / SM ···· ···· »« - · · * • · · · * ·· * -_ · * ·· * 4

-19- * 'and olefin ether and monoglyceride sulphates and sulphosuccinates; nonionic detergents such as fatty acid amine oxides, fatty acid alkanolamides and polyoxyethylene-polypropylene copolymers; and also amphoteric detergents, such as alkyl B-aminopropionates and 2-alkylimidazoline quaternary ammonium salts and mixtures thereof. Alternatively, the compounds of the present invention may be administered in aerosol form, which will deliver the active agent directly to the nasal route, or droplets of the compounds of the invention in a suitable solvent directly into the nasal route.

Formulations of the compounds of the present invention are generally prepared in an amount of about 1 to about 10 minutes. 0.5 kb They contain 25% by weight of the active ingredient in solution. Preservatives and buffers may also be advantageously used in such formulations. Such compositions also contain nonionic surfactants, which have a hydrophilic-lipophilic equilibrium constant (HLB) of about 10% to eliminate or reduce injection site irritation. 12 - approx. Between 17 and. The amount of such surfactant in such formulations will generally be in the range of approx. 5 - approx. 15% by weight. The surfactant may be a single component having the desired HLB value given above, or may be a mixture of two or more components which together provide the desired HLB value. Suitable surfactants for use in parenteral formulations include, for example, polyethylene sorbitan fatty acid esters such as sorbitan monooleate and high molecular weight ethylene oxide and hydrophobic base adducts, such as those obtained by condensation of a propylene oxide with propylene glycol.

The amount of compound of the present invention employed is the amount required to achieve the desired effect, depending on a number of factors. These influencing factors include, for example, the type of compound used, the route of administration, the species, size and age of the treated animal, the route of administration and its frequency, and the route of administration.

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-20 The type of physiological effect on the disease. In each case, the dosage administered will be determined by the operator in the usual manner.

The compounds of the present invention are preferably administered in the form of a composition characterized in that the compound of the present invention is in admixture with a pharmaceutically acceptable carrier, such as any agent that is chemically inactive with the active compound and does not exhibit toxic side effects. . Such formulations can be used for approx. They may contain from 0.1 Rg or less to 500 mg of active ingredient per milliliter of vehicle or about. They may contain up to 99% by weight of the active ingredient in combination with a pharmaceutically acceptable carrier.

In addition, the compounds of the present invention may be included in an inert vehicle and may be assayed for routine serum assays for blood concentration, urine concentration, and the like. may be used according to methods known in the art.

The compositions of the invention may be in solid forms such as tablets, capsules, granules, fixed compositions, nutritional supplements and concentrates, powders, granules or the like. In addition, the compositions of the present invention may be in liquid form, such as a sterile injectable suspension, oral suspension or solution. A pharmaceutically acceptable carrier for use in the composition may be, for example, an inert carrier, a surfactant dispersant, a suspending agent, a tablet binder, a lubricant, a flavoring agent, and a coloring agent. Such useful excipients are described in the literature, such as Remington's Pharmaceutical Manufacturing, 13th Edition, Mack Publishing Co., Easton, Pennsylvania (1965).

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-21 Scheme I and II according to the invention. The following Examples illustrate the preparation of Scheme III. The examples are illustrative only and are not intended to limit the scope of the invention. The reagents and starting materials used in the processes are commercially available or can be prepared by known methods. In the examples, the following abbreviations are used: "eq." equivalent, "g" gram, "mg" milligram, "mmol" millimole, "ml" milliliter, "° C" degree Celsius, "TLC" thin layer chromatography, "R _f " retention constant and "δ" part per million displacement with respect to tetramethylsilane.

Example 1

Preparation of 8- (2-phenylpropyl) -1,3-dipropyl-3,9-dihydropurine-2,6-dione [1,3-di-n-propyl-6-amino] -uracil was suspended in 1 liter of water and 41 ml of a 20% acetic acid solution was added. The mixture was stirred. A solution of 9.03 g of sodium nitrite in 41 ml of water was then added portionwise. Meanwhile, the mixture was maintained at acidic pH by the addition of 12 mL of concentrated hydrochloric acid. The mixture precipitates a purple precipitate. The addition was carried out for 10 minutes and the suspension was stirred for 2 hours. The mixture was filtered and the filtrate was washed with water and dried in vacuo. 46 g of a precipitate are obtained which is 1,3-di-n-propyl-5-nitroso-6-aminouracil.

61.6 g of 1,3-di-n-propyl-5-nitroso-6-aminouracil are suspended in 1 L of water and the suspension is basified to pH 11 with 50% ammonium hydroxide solution. The mixture was then treated with 100 g of sodium dithionite. The reagent was added in portions until the purple color faded. The aqueous mixture was then extracted with chloroform (8 x 200 mL). The extract was dried over magnesium sulfate, filtered and evaporated. The residue was subjected to flash chromatography

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-22 using 5/10% meganol / chloroform as eluent. The product is then recrystallized from 10% isopropanol / hexane followed by 10% isopropanol. 37.29 g of 1,3-di-n-propyl-5,6-diaminouracil are obtained. Mp 127-128 ° C.

3-Phenylbutanoic acid (1.0 g, 6.1 mmol) was dissolved in tetrahydrofuran (20 mL) and N-methylmorpholine (0.67 mL, 6.1 mmol) was added. The reaction mixture was then cooled to -20 ° C and isobutyl chloroformate (0.79 mL, 6.1 mmol) was added. The resulting mixture was stirred for 20 minutes and then a solution of 1.4 g (6.1 mmol) of 1,3-di-n-propyl-5,6-diaminouracil in 5 ml of dimethylformamide was added. The reaction mixture was stirred at -20 ° C for 3 hours and then diluted with diethyl ether (400 mL). The layers were separated and the organic layer was washed with saturated aqueous sodium bicarbonate (200 mL) and brine (50%, 2 x 200 mL). The organic phase was dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. 2.23 g of N- (2-amino-4,6-dioxo-3,5-dipropylcyclohex-1-enyl) -3-phenylbutyramide are obtained.

N- (2-Amino-4,6-dioxo-3,5-dipropyl-cyclohex-1-enyl) -3-phenyl-butyramide (2.23 g, 6.2 mmol) was dissolved in ethanol (100 mL) and treated with 15 ml of a 15% aqueous solution of potassium hydroxide are added. The reaction mixture was heated to 60 ° C for 3 hours. The mixture was cooled and acidified with concentrated hydrochloric acid (22 mL). The resulting mixture was extracted with 500 ml of diethyl ether. The organic solution was washed with water (200 mL) and saturated aqueous sodium chloride (200 mL). The organic solution was then dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was worked up with 10% diethyl ether / hexane. The solid was filtered and purified by radial chromatography using 50% ethyl acetate / hexane on a 4 mm plate. 180 mg of the title compound are obtained. Mp 136-137 ° C.

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-23Elemanalízis for C ₂ OH 2 ₄ 0 ₆ N ₂ O: C, 67.77; H, 7.39; N, 15.81; Found: C, 67.66; H, 7.39; N, 15.74.

Example 2

Preparation of 1,3-Dipropyl-8- (1,2,3,4-tetrahydronaphthalen-2-yl) -3,9-dihydropurine-2,6-dione [Compound (III)]

A solution of 1,2,3,4-tetrahydro-2-naphthoic acid (1.0 g, 5.67 mmol) in tetrahydrofuran (40 mL) was obtained. N-methylmorpholine (0.62 mL, 5.62 mmol) was added and the mixture was cooled to -20 ° C. Isobutyl chloroformate (0.73 mL, 5.67 mmol) was added and the mixture was stirred for 25 min. A solution of 1,3-di-N-propyl-5,6-diaminouracil (1.28 g, 5.67 mmol) in dimethylformamide (5 mL) was then added. The reaction mixture was stirred at -20 ° C for 5 hours. The mixture was warmed to room temperature and diluted with diethyl ether (300 mL). The layers are separated and the organic phase is washed with 200 ml of saturated aqueous sodium bicarbonate solution and then with 200 ml of saturated aqueous sodium chloride solution. The organic solution was then dried over anhydrous magnesium sulfate, filtered and the solvent was evaporated. The residue was purified by radial chromatography using a 2-4-6% methanol / chloroform gradient on a 4 mm plate. Foam is obtained in a yield of 2.0 g of 1,2,3,4-tetrahydronaphthalene-2-carboxylic acid (2-amino-4,6-dioxo-3,5-dipropyl-cyclohex-1-enyl) -amide.

1,2,3,4-Tetrahydronaphthalene-2-carboxylic acid (2-amino-4,6-dioxo-3,5-dipropyl-cyclohex-1-enyl) (2.0 g, 5.2 mmol) - amide was dissolved in 50 ml of ethanol and 50 ml of 15% potassium hydroxide solution was added. The mixture was heated to 70 ° C for 4 hours and then cooled to 0 ° C. The mixture was then acidified with concentrated hydrochloric acid (13 mL). Water (100 mL) was added to the mixture and the mixture was precipitated

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The precipitate was filtered off under vacuum. The white solid was purified by flash chromatography using 50% ethyl acetate / hexane as eluent. The product is triturated with 5% diethyl ether / hexane and filtered and dried. Drying was carried out for 30 minutes at 120 ° C under vacuum. 1.04 g of the title compound are obtained. Mp: 202-204 ° C.

Analysis calculated for C 21 H ₂₆ N ₄ O ₂ : C, 68.83; H, 7.15; N, 15.29;

Found: C, 68.72; H, 7.11; N, 15.30.

Example 3

Preparation of 8- (trans-2-phenylcyclopentyl) -1,3-dipropyl-3,9-dihydropurine-2,6-dione [Compound (IV)] g of 1,3-diallyl-6-amino- uracil is suspended in 400 ml of water. Suspend in a 1 liter round bottom flask equipped with a stirrer. Then 6.7 ml of a 20% acetic acid solution are added. Thereafter, 2 ml of concentrated hydrochloric acid was added periodically. A solution of sodium nitrite (1.53 g) in water (7 ml) was then added. The mixture was stirred for 4 hours and the resulting precipitate was filtered off. The precipitate was washed with water, then collected and dried at 80 ° C for 20 hours under vacuum. 4.54 g of 1,3-diallyl-5-nitroso-6-aminouracil are obtained. The product is a purple solid. Mp 170-180 ° C (87% yield).

4.5 g of 1,3-diallyl-5-nitroso-6-aminouracil are suspended in 150 ml of ethyl acetate and a solution of 23.6 g of sodium dithionite in 64 ml of water is added to the suspension. After stirring for 1 hour, the layers were separated and the aqueous layer was extracted with ethyl acetate (4 x 100 mL). The combined organic solutions were dried over magnesium sulfate, filtered and the solvent was evaporated. The rest is fast-cro

61.335 / SM using 10% methanol / chloroform as eluent.

4.41 g of 1,3-diallyl-5,6-diaminouracil are obtained.

1.0 g (5.3 mmol) of F.G. Bordwell and J. Almy, J. Org. Chem., 38, 571 (1973). A solution of trans-2-phenylcyclopentanecarboxylic acid prepared in 20 ml of tetrahydrofuran was prepared and treated with 0.58 ml (5.3 mmol) of N-methylmorpholine. The reaction mixture was cooled to -20 ° C and 0.69 ml (5.3 mmol) of isobutyl chloroformate was added. After stirring for 30 min, a solution of 1,3-diallyl-5,6-diaminouracil (1.2 g, 5.3 mmol) in dimethylformamide (4 mL) was added. The resulting mixture was stirred at -20 ° C for 3 hours, then warmed to room temperature and diluted with 400 mL of diethyl ether. The phases are separated and the organic phase is washed with 2 x 200 mL of saturated sodium bicarbonate solution and 2 x 300 mL of 50% aqueous sodium chloride. The organic solution was then dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified by radial chromatography on a 2 mm plate using a gradient of 2-5% methanol / chloroform. 0.51 g of trans-2-phenylcyclopentanecarboxylic acid (3,5-diallyl-2-amino-4,6-dioxocyclohex-1-enyl) -amide is obtained.

Trans-2-phenylcyclopentanecarboxylic acid (3,5-diallyl-2-amino-4,6-dioxocyclohex-1-enyl) amide (300 mg, 0.76 mmol) was dissolved in ethanol (100 mL), 100 ml of 10% potassium hydroxide solution are added. The mixture was heated to 60 ° C for 4 hours, cooled and then diluted with water (200 mL). The mixture was acidified with concentrated hydrochloric acid and extracted with diethyl ether (400 mL). The organic extract was washed with water (200 mL), brine (200 mL) and dried over anhydrous magnesium sulfate. The mixture was filtered and the solvent evaporated in vacuo. The residue is assisted by radial chromatography61.335 / SM

It is purified at -26 using 40-50% ethyl acetate / hexane on a 2 mm plate. 149 mg of 5,7-diallyl-2- (2-phenylcyclopentyl) -1,7-dihydro-benzoimidazole-4,6-dione are obtained.

5,7-Diallyl-2- (2-phenylcyclopentyl) -1,7-dihydro-benzoimidazole-4,6-dione (139 mg, 0.37 mmol) was dissolved in methanol (20 mL). A catalytic amount of 10% palladium on charcoal was added to the solution and the mixture was stirred under a hydrogen atmosphere. Stirring is carried out for 45 minutes when the hydrogenation is complete. The reaction mixture was then purged with a stream of nitrogen and then filtered, using a diatomaceous earth filter aid. The filtrate was evaporated in vacuo and the residue was purified by radial chromatography on a 2 mm plate using 40-50% ethyl acetate / hexane gradient. 98 mg of the title compound are obtained. Mp: 152-153 ° C.

Analysis calculated for C22 H28 N4 O2: C, 69.45; H, 7.42; N, 14.72; Found: C, 69.36; H, 7.56; N, 14.63.

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Claims (15)

PATENT CLAIMS What is claimed is: 1. A compound of formula (I), including its (R) - and (S) -enantiomers and racemic mixtures, and pharmaceutically acceptable salts thereof, wherein: R ₁ and R ₂ are each independently C 1-4 alkyl or C 2-4 alkenyl; Z is a group of formula (a) or a group of formula (b) wherein R ₃ is hydrogen, C 1-3 alkyl, nitro, amino, hydroxy, fluoro, bromo or chloro and n is 1 or 2. The 8- (2-phenylpropyl) -1,3-dipropyl-3,9-dihydropurine-2,6-dione of claim 1. The 1,3-dipropyl-8- (1,2,3,4-tetrahydronaphthalen-2-yl) -3,9-dihydropurine-2,6-dione of claim 1. The 8- (trans-2-phenylcyclopentyl) -1,3-dipropyl-3,9-dihydropurine-2,6-dione of claim 1. 5. A pharmaceutical composition comprising the compound of claim 1 and a pharmaceutically acceptable carrier. 6. Use of a compound according to any one of claims 1 to 6 as a pharmaceutically active compound. 7. Use of a compound according to any one of claims 1 to 5 as an agent acting on a selective adenosine receptor. Use of a compound according to claim 1 as an A-1 or A-2 adenosine receptor selective agonist. 61 335 / SM The compound of claim 1 for use as an A-1 or A-2 adenosine receptor selective antagonist. The compound of claim 1 for selectively reducing blood pressure. A compound according to claim 1 for selectively reducing heart rate. Use of a compound according to claim 1 together with a pharmaceutically acceptable carrier for the manufacture of a medicament for the selective lowering of blood pressure. Use of a compound according to claim 1 together with a pharmaceutically acceptable carrier for the manufacture of a medicament for selectively reducing heart rate. A process for the preparation of a compound of formula (I), its (R) - and (S) -enantiomers or racemic mixtures thereof, and pharmaceutically acceptable salts thereof, wherein: R! and R ₂ is independently C 1-4 alkyl or C 2-4 alkenyl; Z is a radical of formula (a) or a radical of formula (b) wherein R ₃ is hydrogen, C 1-3 alkyl, nitro, amino, hydroxy, fluoro, bromo or chloro; and n is an integer of 1 or 2, wherein the compound of formula (I), wherein R _n R ₂ and Z are as defined above, is reacted with 10 to 20% aqueous solution of a suitable base in an organic solvent and the reaction is carried out for ca. 40-60 ° C for approx. It is carried out for 1-6 hours. 61 335 / SM A process for the preparation of a compound of formula (Ia), including their (R) - and (S) -enantiomers and their racemic mixtures and pharmaceutically acceptable salts thereof, wherein R 1 and R ₂ 'are independently C 2 -C 4 and Z is a group of the formula (a) or (b), wherein R ₃ is hydrogen, C 1-3 alkyl, nitro, amino, hydroxy, fluoro, bromo, or chloro; and n is 1, or 2, characterized in that the compound of formula (I) wherein in formula Z is as defined above, and R ι and _R2 are independently 2-4 lower alkenyl group, a suitable in the presence of a hydrogenation catalyst in a suitable organic solvent under a hydrogen atmosphere for 30 minutes to 4 hours.